getImageCompression

Get the compression filter used on an image.
getImageCompression([in] int idx, [out, retval] BSTR *comp)
This function returns the compression filter, if any, used on the idxth image on the page specified in the last call to getImages.

The compression filter names (as of PDF 1.7) are: LZWDecode, RunLengthDecode, CCITTFaxDecode, DCTDecode (JPEG), FlateDecode, JBIG2Decode, and JPXDecode (JPEG 2000).

VB6:
pdf.getImages 1 nImgs = pdf.numImages For i = 0 To nImgs-1 comp = pdf.getImageCompression(i) MsgBox "image " & i & ": " & comp & " compression" Next i
getImages
numImages